Tenable
Tenable (ten"ȧ*b'l) , adjective
[French tenable, from tenir to hold, Latin tenere. See Thin, and compare Continue, Continent, Entertain, Maintain, Tenant, Tent.]
Capable of being held, maintained, or defended, as against an assailant or objector, or against attempts to take or process; as, a tenable fortress, a tenable argument.
If you have hitherto concealed his sight,
Let it be tenable in your silence still.
I would be the last man in the world to give up his cause when it was tenable.